1. Field of the Invention
The present invention relates generally to apparatus for intravenous (I.V.) infusion and effusion of blood, bodily fluids and medications, and it more specifically relates to a method and apparatus for the initial insertion of an I.V. catheter and for secure coupling of various I.V. apparatus thereto.
2. Description of the Related Art
One of riskiest procedures modern health care workers are asked to perform is starting I.V.'s. The common current practice is to drive a guide needle carrying a cannula into a patient's vein, and then to withdraw the guide needle, leaving the cannula in place. Upon withdrawal of the guide needle, the blood, under normal venous pressure, fills the cannula and has the natural tendency to flow out of the cannula's proximal end. If unimpeded, blood will continue to flow from the cannula until the health care worker couples the cannula to such I.V. apparatus as an I.V. line, a syringe or a heparin lock.
As the prevalence of AIDS, hepatitis and other blood-borne diseases is now higher than ever, and as health care workers are acutely aware of the special risks of working with blood, successful installation of a cannula in a vein commonly triggers an awkward scramble wherein, with the finger of one hand, the worker attempts to plug the flow of blood from the cannula or to press on the vein, and with the remaining hand attempts to grasp and align the intended I.V. apparatus and to couple it with the cannula. In the meantime, the guide needle is often hastily discarded, sometimes simply by being stuck into a mattress or dropped to the floor.
Daily, workers such as emergency room nurses may have to start as many as two dozen or more I.V.'s and, in a single hospital, more than several hundred may be required in any given day. Although workers commonly take the precaution of wearing rubber gloves to avoid contact with inevitably spilled blood, gloves are an insufficient barrier when working with sharp, contaminated needles, especially in the emergency room environment where the medical histories of patients are often completely unknown.
When conventional methods and equipment such as those described above are employed, each I.V. start presents a separate health-risking event. Indeed, even at best, these methods and equipment result in the necessity of clean-ups which, if they were avoidable, would at least lighten the workload of hospital staff.
Many devices for preventing back-flow in I.V. apparatus are known. And, several may be useful for starting I.V.'s, as well. Examples include the catheter adapter and valve disclosed in U.S. Pat. No. 5,085,645 issued to Purdy, et al. in 1992; and, the one-way septum and valve assembly shown in U.S. Pat. No. 4,842,591 issued to Luther in 1989. However, although such devices have now been available for some time, their use is has not been widely adopted. One reason may be that the moderate mechanical complexity of these disposable items makes them a bit more expensive than is desirable. Further, health care workers are somewhat more resistant to changing procedures and equipment than may be reasonable, but in any case, this stubbornness in the profession may continue to prevent adoption of such unfamiliar improvements.
Simpler constructions include U.S. Pat. No. 5,078,689 issued to Keller in 1992; and, U.S. Pat. No. 5,295,969 issued to Fischell, et al. in 1994. But, these are adapted to effusion of larger fluid volumes and, even if scaled-down are not well suited for use as peripheral I.V.'s.
A relatively simple I.V. catheter having a resilient valve therewithin is shown in U.S. Pat. No. 5,098,396 issued to Taylor, et al. in 1992. However, the valve of the Taylor, et al. device appears somewhat less than secure because its design would cause it to fail open rather than to fail closed. Further, although hands-free once locked, the Taylor, et al. valve is not automatic; it requires manipulation each time its orientation is changed. Yet further, the valve of the Taylor et al. device is not at all compatible with the relatively standard structure of the most commonly used catheters. Thus, for the industry and the profession to adopt its use, its unique cooperating hub and compression ring would also be required. In contrast, it would seem much more expedient for all concerned if a valve or equivalent element compatible with the shape and dimensions of most ubiquitously-used peripheral I.V. catheter structure were available.
Further, one drawback of all of the foregoing devices is that they provide but a single means for fluid containment; no backup or fail-safe mechanism is inherent in those designs. Thus, it would be beneficial if a peripheral I.V. catheter included means for secondary containment in case the primary fluid-sealing element began to leak.